This article discusses the incidence of constipation in an intensive care unit. Disorders of the gastrointestinal motility are frequent among critically ill patients. Nevertheless, constipation has received less importance in this matter. Several alimentary factors and of the clinical treatment have been associated to this event. Constipation is the condition in which bowel movements are infrequent or incomplete during three, six or nine consecutive days, or otherwise because of the necessity to assist to the treatment with evacuating measures. The authors conducted a descriptive, quali-quantitative, transversal and prospective design of the incidence of constipation and its implications on the progress of critically ill patients, in patients 18 years old or older, assisted at the Intensive Care Unit from the Hospital “Juan Fernandez”, from Buenos Aires. It is concluded that constipation is a frequent complication among critically ill patients and thus the administration of early enteral nutrition with insoluble fiber should be considered, as a protector support against constipation. Accelerating gastrointestinal recovery during intensive care stay could increase patient comfort, decrease the average hospital stay and reduce costs and readmission rates.